Neuroblastoma is one of the most common solid tumors in children and is originated from the sympathoadrenal lineage of the neural crest (Bolande, 1974: non-patent document 1). Its clinical behavior is heterogeneous: the tumors found in infants frequently regress spontaneously by inducing differentiation and/or programmed cell death, while those occurred in the patients over one year of age are often aggressive and acquire the resistance to intensive chemotherapy. Though the recent progress in the therapeutic strategies against advanced stages of neuroblastomas has improved the survival rate, the long-term results are still very poor. In addition, some of the tumors categorized to the intermediate group (in stage 3 or 4, and possessing a single copy of the MYCN gene) often recur after a complete response to the initial therapy. It is conceivable that such differences in the final outcome among the tumors maybe due to the differences in genetic and biological abnormalities which are reflected to the expression profile of genes and proteins in the tumor.
The prediction of the prognosis is one of the most emergent demands for starting the treatment of neuroblastoma. A patient's age (over or under one year of age), as expected from the natural history of neuroblastoma, is an important factor to segregate the outcome into favorable and unfavorable groups (Evans et al., 1971: non-patent document 2). The disease stage is also a powerful indicator of prognosis (Brodeur et al., 1993: non-patent document 3). Moreover, recent advances in basic research have found more than several molecular markers which are useful in the clinic. They include amplification of MYCN oncogene (Schwab et al., 1983: non-patent document 4; Brodeur et al., 1984: non-patent document 5), DNA ploidy (Look et al., 1984, 1991: non-patent document 6, 7), deletion of chromosome 1p (Brodeur et al., 1988: non-patent document 8) and TrkA expression (Nakagawara et al., 1992, 1993: non-patent document 9, 10), some of which are already used as prognostic indicators to choose the therapeutic strategy at the bedside. The other indicators also include telomerase (Hiyama et al., 1995: non-patent document 11), CD44 (Favrot et al., 1993: non-patent document 12), pleiotrophin (Nakagawara et al., 1995: non-patent document 13), N-cadherin (Shimono et al., 2000: non-patent document 14), CDC10 (Nagata et al., 2000: non-patent document 15), and Fyn (Berwanger et al., 2002: non-patent document 16). However, even their combination often fails to predict the patients' outcome. Therefore, new diagnostic tools in the postgenomic era have been expected to become available. Recently, DNA microarray method has been applied to comprehensively demonstrate expression profiles of primary neuroblastomas as well as cell lines. It has already identified several genes differentially expressed between favorable and unfavorable subsets (Yamanaka et al., 2002: non-patent document 17; Berwanger et al., 2002: non-patent document 16) or the genes changed during retinoic acid-induced neuronal differentiation (Ueda, 2001: non-patent document 18). However, the study to predict the prognosis by microarray using a large number of neuroblastoma samples has never been reported.
The present inventors have recently isolated 5,500 independent genes from the cDNA libraries generated from the primary neuroblastomas, a part of which has been previously reported (Ohira et al., 2003a, 2003b: non-patent document 19, 20). Further the present inventors have files patent applications relating to full disclosure of the isolated genes, and a relationship between the outcome predictability of neuroblastoma and the genes' expressions (patent documents 1-5)
Patent documents
    1: JP 2001-245671A    2: JP 2001-321175A    3: PCT/JP01/01631 pamphlet    4: PCT/JP01/01629 pamphlet    5: JP2004-147563ANon-patent documents    1: Bolande, R. P. Hum Pathol 5, 409-429 (1974).    2: Evans, A. E. et al. Cancer 27, 374-8 (1971).    3: Brodeur, G. M. et al. J Clin Oncol 11, 1466-77 (1993).    4: Schwab, M. et al. Nature 305, 245-8 (1983).    5: Brodeur, G. M. et al. Science 224, 1121-4 (1984).    6: Look, A. T. et al. N Engl J Med 311, 231-5 (1984).    7: Look, A. T. et al. J Clin Oncol 9, 581-91 (1991).    8: Brodeur, G. M. et al. Prog Clin Biol Res 271, 3-15 (1988).    9: Nakagawara, A. et al. Cancer Res 52, 1364-8 (1992).    10: Nakagawara, A. et al. N Engl J Med 328, 847-54 (1993).    11: Hiyama, E. et al. Nat Med 1, 249-55 (1995).    12: Favrot, M. C. et al. N Engl J Med 329 (1993).    13: Nakagawara, A. et al. Cancer Res 55, 1792-7 (1995).    14: Shimono, R. et al. Anticancer Res 20, 917-23 (2000).    15: Nagata, T. et al. J Surg Res 92, 267-75 (2000).    16: Berwanger, B. et al. Cancer Cell 2, 377-86 (2002).    17: Yamanaka, Y. et al. Int Oncol 21, 803-7 (2002).    18: Ueda, K. Kurume Med J 48, 159-64 (2001).    19: Ohira, M. et al. Oncogene 22, 5526-36 (2003a).    20: Ohira, M. et al. Cancer Lett 197, 63-8 (2003b).